Frequency multipliers are often used in microwave/millimeter-wave signal sources. A frequency multiplier can up-convert a relatively low frequency signal into a high frequency signal. Drawbacks exist with conventional frequency multipliers. For example, some conventional frequency multipliers have a low conversion gain and a limited operating frequency, while others consume large amounts of power and require a relatively high supply voltage. What is desired is a frequency multiplier that overcomes at least some of these disadvantages.